This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The Transgenic Mouse and Knockout Core creates transgenic animals for Brown, affiliated hospital, and re-gional investigators. This facility includes a stand-alone microinjection facility capable of handling both pro-nuclear and blastocyst microinjections. An ES cell facility is attached to the core;its function is to perform gene targeting manipulations with vectors supplied by investigators. The facility also advises investigators on optimal strategies for the construction of vectors. With the exception of vector construction, the core handles all aspects of the production of transgenic animals. The core also advises investigators on follow up breeding regimens and analysis of the transgenic animals.